YANGON, Myanmar (CNN) -- Residents in this sprawling river delta city hacked their way through downed trees and trudged through knee-deep swirling brown waters Monday as they tried to pick up the pieces of their lives after a deadly cyclone ravaged the southeast Asian country over the weekend.

The International Federation of Red Cross and Red Crescent Societies said it has released 200,000 Swiss Francs (about $190,000) to help with the aftermath.

"I think one of the biggest needs right now is to stave off disease," said spokesman Eric Porterfield. "We will be helping with the distribution of clean drinking water and setting up shelters."

Working with the Myanmar Red Cross agency, the International Red Cross is distributing drinking water, plastic tarps to cover roofs and blankets, among other items.

The tropical cyclone, packing winds of up to 150 miles (241 km) per hour, slammed into Myanmar over the weekend, killing as many as 350 people.

"We believe hundreds of people are dead," said Khin Maung Win with the Democratic Voice of Burma -- a broadcast media group run by opposition expatriates. "The entire lower Burma is affected. In some areas, entire villages disappeared."

The activist group opposed the military rule in Myanmar, formerly known as Burma.

The ruling junta declared a state of emergency in five regions: the city of Yangon, Irrawaddy, Pegu and the states of Karen and Mon. All flights to Yangon, the former capital, were canceled. Learn more about Myanmar »

Don't Miss

The storm ripped through the sprawling river delta city of Yangon for more than 10 hours -- from Friday night until Saturday noon, said Burma Democratic Concern. Watch the cyclone hammer Yangon »

By Sunday, many parts of the city were without electricity. Phone connections were also down in most areas, making it difficult to assess the extent of the damage.

"Most Burmese with whom we've been in touch report they lost their roofs, although so far everyone we have been able to contact reports that they and their families are safe," said a Yangon-based diplomat who requested anonymity because he was not authorized to speak to the media.

Earlier Monday, an editor for an independent Myanmar newspaper based in Thailand told CNN that people in the Southeast Asian nation were angry over the response to the disaster by the ruling military junta.

"People are very angry with the slow response coming from the military government," said Aung Zaw of Irrawaddy news magazine.

Zaw said communication was down across large areas of the country. He also said the casualty figures could rise.

"Fuel is not easily available. International emergency assistance would be needed within seven days. There is no food for eating," Win said.

Food prices -- already on a dramatic rise -- climbed further. Long lines could be seen at gas stations in Yangon. Many of the stations were operating on generators. At one gas station more than 100 buses lined up to refill.

"International emergency assistance would be needed within seven days," the diplomat said.

The junta has scheduled a May 10 referendum on a new constitution for the country, which came under sharp criticism from many nations for using force to suppress pro-democracy protests last year.E-mail to a friend